Building public support for climate mitigation is a key prerequisite to making meaningful strides toward decarbonization and achieving net-zero emissions. Using nationally representative, individual-level surveys for 28 countries, this paper identifies the current levels and drivers of support for climate mitigation policies. Controlling for individual characteristics, we find that pre-existing beliefs about policy efficacy, perceived costs and co-benefits (e.g., cleaner air), and the degree of policy progressivity are important drivers of support for carbon pricing policies. The knowledge gap about climate mitigation policies can be large, but randomized information experiments show that support increases (decreases) after individuals are introduced to new information on the benefits (potential costs) of such policies.